In the search for hydrocarbons and development of hydrocarbon-bearing wells, oilfield operators drill boreholes and perform well completion operations. Example well completion operations include installation of casing sections along a borehole, where each casing section includes multiple casing segments. The drilling crew attaches the casing segments together to form the casing section as it is being lowered into the borehole to a desired position. Once the crew achieves the desired length and position for a particular casing section, they cement it in place to create a permanent casing section installation. The crew may then extend the borehole by drilling through the terminus of the installed casing section. The process of installing casing sections and extending a borehole can be repeated as desired.
During drilling and/or well completion operations, the rotation of the drill string causes frictional wearing along the contact surfaces between the drill string and the casing. Over time, such wearing reduces casing side-wall thickness, degrading the casing strength and integrity. Failure of a casing segment due to wear may result in expensive well repair operations and/or abandoning a well.
Several wireline logging techniques have been developed to measure casing wear. Available wireline logging techniques involve lowering or raising logging tools along the interior of the one or more installed casing sections. Example casing wear logging tools employ acoustic, electromagnetic (EM), or multi-finger caliper technology. While it may be possible to reduce casing failures by frequently and repeatedly deploying casing wear logging tools, such a procedure is not economically feasible as it increases costs and significantly slows the drilling process. Other economically undesirable options to reduce casing failure include using excessively thick casing segments or the employment of high-grade and high-quality piping materials.
As an alternative to the use of overly-conservative thick casing, expensive high-grade casing materials, or the frequent re-logging of casing thickness, some operators rely on physics-driven models to estimate casing wear. Such models often become unworkably complex and/or exhibit large inaccuracies, despite repeated recalibration efforts.
It should be understood, however, that the specific embodiments given in the drawings and detailed description thereto do not limit the disclosure. On the contrary, they provide the foundation for one of ordinary skill to discern the alternative forms, equivalents, and modifications that are encompassed together with one or more of the given embodiments in the scope of the appended claims.